The last episode closed with a thought-provoking passage from the Meditations of Marcus Aurelius that places our human reason into the proper Stoic perspective. It reads:

to have the intellect as a guide towards what appear to be duties is something that we share with those who do not believe in the gods, with those who betray their country, with those who will do anything whatever behind locked doors. (Meditations 3.16)

As a transition to this episode, I will highlight the important point Marcus makes in this passage for a second time. Human reason is not the ultimate guide for ethical behavior in Stoic practice. On the contrary, universal Reason—cosmic Nature—is the sole arbiter of good and bad in Stoicism. Chrysippus, the third scholarch of the Stoa, argued this point when he wrote:

For there is no other or more suitable way of approaching the theory of good and evil or the virtues or happiness than from the universal nature and from the dispensation of the universe… For the theory of good and evil must be connected with these, since good and evil have no better beginning or point of reference and physical speculation is to be undertaken for no other purpose than for the discrimination of good and evil.[1]

Again, in his book titled On Ends, Chrysippus argued:

And this is why the end may be defined as life in accordance with nature, or, in other words, in accordance with our own human nature as well as that of the universe, a life in which we refrain from every action forbidden by the law common to all things, that is to say, the right reason which pervades all things, and is identical with this Zeus.[2]

In this passage, Chrysippus makes it quite clear a “life in accordance with nature” is one lived in agreement with “the right reason which pervades all things, and is identical with this Zeus” (emphasis added). The Greek word translated as “reason” in this passage is logos. According to the Stoics, every entity that exists is comprised of a mixture of matter (the passive principle) and pneuma(the active principle). Humans are unique among all existing entities because the pneuma within us comprises our soul (psyche) and “constitutes itself as reason, logos.”[3] Seneca articulated this as follows:

What, then, is the distinctive property of a human being? Reason. It is by reason that the human surpasses animals and is second to the gods. Therefore perfected reason is the human’s distinctive excellence; everything else is shared with animals and plants. (Letters 76.9)

As A.A. Long emphasizes, “The [goal-directed] assumptions which this argument requires for its validity are too obvious to need discussion.” Accordingly, “'the goodness of living according to reason' is derived from, and not the grounds of, 'living according to Nature'.” In other words, any “goodness” we can attribute to living according to human reason is due solely to the fact that human reason is derived from cosmic Reason (logos). Therefore, the Stoics looked to Nature for ethical norms to guide our lives and society. Chrysippus articulated this in his“third book on the Gods,” where he wrote:

It is not possible to discover any other beginning of justice or any source for it other than from Zeus and from the universal nature, for thence everything of the kind must have its beginning if we are going to have anything to say about good and evil.[4]

In his paper titled The Logical Basis for Stoic Ethics,